There is a variety of fittings available on the market today. One class of fittings, hydraulic or pneumatic fittings, involve deformation or flaring of the tube or workpiece on which they are applied; another class of fittings employs a wedging action by taper rings thereby sealing the workpiece but again deforming the workpiece. A nut is generally used to provide the required compressional force.
Split head clamping fasteners have been known for some time, particularly in the field of electrical connectors. Patents illustrating such fasteners include U.S. Pat. Nos. 368,149; 1,802,381; 2,406,346; and 2,440,828 for holding electrical wires.
Although these prior art type of fittings and fasteners are useful, they have several drawbacks including the use of several mating parts, deformation of the workpiece, multiple turns at high strength of the forcing nuts, and rotation of the workpiece within the fitting as it is tightened.